| abstract |
A high-strength cold-rolled steel sheet having high ductility and excellent stretch flangeability is provided. A high-strength cold-rolled steel sheet has a component composition of mass%, C: 0.06% to 0.12%, Si: 0.4% to 0.8%, Mn: 1.6. %: 2.0% or less, Cr: 0.01% or more, 1.0% or less, V: 0.001% or more, 0.1% or less, P: 0.05% or less, S: 0.01% or less, Sol. Al: 0.01% or more and 0.5% or less, N: 0.005% or less, the balance is composed of iron and inevitable impurities, and the volume ratio of equiaxed ferrite in the metal structure is 50% The martensite volume fraction is 5% or more and 15% or less, the volume ratio of the retained austenite phase is 1% or more and 5% or less, the average particle size of the retained austenite phase is 10 μm or less, and the aspect ratio of the retained austenite phase Is 5 or less, and the remaining structure is composed of bainite and / or pearlite. [Selection figure] None |